A man who admitted to attacking his grandmother with a hammer and cutting her throat is facing murder charges after the woman died from her injuries.

Andrea Campa, 59, was found bleeding to death at her home in the 900 block of Rigsby Avenue on Saturday night. She was rushed to San Antonio Military Medical Center, where she was pronounced dead about 3:40 a.m. Wednesday.

The woman's grandson, John Anthony Campa, flagged officers down as they rushed to the family's home Saturday and confessed to beating the woman in the head with a hammer and slitting her throat.

The younger Campa was charged with aggravated assault of a relative causing serious bodily injury, but the change was upgraded to murder, officials said Thursday. He remains behind bars in lieu of $30,000 bail.